The twist is in the method the user may exploit in order to control the planes, using a brain-computer interface. Writes Byron:
As for the control mechanism, we actually have some devices that are able to read brianwaves and infere what the user is thinking about, so the choice was easy. The newest and most promising headset for thought control is the epoc, not yet on the market, but with a free SDK I can play with. With this technologies I was actually able to develop something that works and doesn't need any special stuffs you can't buy off the shelf. In the story, the players controls 3 airplane each, but in practice it was too hard to simultaneusly control 3 airplanes, so I reduced the number to a single airplane for each player. Furthermore, since the airplanes are not projected into the real world, it's suggested you wear a HMD.
You can download the binaries and source code and learn more about this interesting project here.